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Articles for "Renewable energies"

Solar power station in South Africa. Khi Solar One in the Northern Cape region – designed for a capacity of 50 megawatts – will soon be connected to the grid.

The Sun almost always shines in the Kalahari, which extends across the Northern Cape region in South Africa. The area enjoys 4000 sunlight hours and an average solar irradiance of up to 2800 kilowatt-hours per square metre per year; by comparison, Spain reaches no more than 2300. Therefore, it follows that the currently untapped potential for solar power is immense.

South Africa's main source of electricity is coal (90 percent). Could solar power stations bring about change? Experts in science, industry and politics will discuss this exact question at the SolarPACES Conference. They will also pool their opinions on innovation regarding solar thermal power plants, storage technologies and the use of solar energy to produce fuels. read more

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Whether on the road, by sea or in the air – the basis of modern transport systems is the internal combustion engine. Hardly any other invention has resulted in so many variants in just 100 years of development. One of the reasons for the technical success of diesel and petrol combustion engines is the high energy content of the fuel they burn. But how much energy do fossil fuels really contain, in comparison with hydrogen or lithium ion batteries?
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The twelve offshore wind turbines that make up the 'alpha ventus' wind farm, 45 kilometres to the north of the North Sea island of Borkum, can generate sufficient electricity for 50,000 households. Like all other wind farms in the North Sea, these turbines are installed on firm foundations at water depths of between 30 and 50 metres. However, not all coastal countries have such a flat and shallow seabed immediately off their coastline. Might it not be a great deal simpler and less expensive to install wind turbines on floating platforms?
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A growing volume of energy originating from renewable sources is being used right around the world – from Europe to America to China. This trend is especially widespread in the electricity-generation sector. Over the last couple of years, the USA and the countries of the EU have been building more power station capacity based on wind, water and solar energy than they in conventionally fuelled power stations, – that is, coal, gas or uranium. However, is any country already able to meet all of its energy needs from renewable sources?
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In January 2010, wind farms in Germany had a generating capacity of 25,777 megawatts. This means that almost eight percent of Germany's electricity requirement can be met in a climate-neutral way. However, since land areas exposed to strong winds are limited, both large and small-scale power-generating businesses are jostling for position out in the open sea. This poses a simple question: are offshore wind farms genuinely more efficient?
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Electricity has been generated from tidal power for decades. Large installations could supply entire towns and cities. However, tides are not the only forces moving water in our seas. Ocean currents also move huge amounts of water all around the globe. Is it worth exploiting this power source?
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Two trends are emerging for future renewable electricity. In the first, local solar, wind or biomass plants will produce more energy for small communities or single homes. In the second, large amounts of electricity will be generated by solar power stations in desert areas or extensive offshore wind farms, and delivered over long distances to densely populated areas. But how can electrical power be delivered over long distances without large losses?
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Under the influence of the Moon's gravity, the water of Earth's oceans rises and falls twice a day. Powerful forces are at work all over the globe between every low and high tide – forces that can be harnessed to generate electrical power. Just how mature is the technology and what is the potential that tidal power stations could unleash?
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After decades of planning, Belo Monte - the third largest hydroelectric power station in the world, will now be constructed in the Amazonas region of northern Brazil. When the Brazilian Institute of Environment and Renewable Natural Resources, IBAMA, approved the plan in early February, it was met with vociferous criticism from environmental conservationists and spokespersons for indigenous groups. So just how green are gigantic hydroelectric power stations really?
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